Extracorporeal life support (ECLS) is used for newborn infants with respiratory failure. Improved long term ECLS efficiency is desirable and would allow broader (children/adults/ cardiac support) and safer use. Systems are based on microporous (hollow fiber) membranes or silicon non- porous membranes. Microporous membranes have adequate initial performance but after 2-6 hours "plasma leakage" clogs the pores and gas transport drops significantly. Silicone membranes are more stable but gas permeabilities are much lower. Also silicone is not workable. This leads to configurations with higher priming volume and poor blood side flow and associated poor gas transport. We propose developing novel high permeability perfluoropolymers into hollow fiber (HF) membranes with excellent oxygen and carbon dioxide transport. Using thin film fabrication techniques demonstrated on related polymers we will make HF modules with stable carbon dioxide and oxygen fluxes 20 times higher than silicone and significantly higher than demonstrated in non-porous ECLS operation. Phase I will demonstrate our ability to fabricate high flux hollow fibers and project extracorporeal membrane oxygenator (ECMO) performance. In Phase II we will optimize performance, make larger HF modules, perform ECLS tests, and evaluate biocompatibility.